I've shot about 75 deer over the last 32 years with 2 blade Zwickey Delta, 2 blade Magnus 125's, 2 blade grizzly, 2 blade Eclipse, 3 blade razorcaps and 3 blade Kustom King Trailmakers.
I've been on trails of at least 50 more up at Shrewhaven with varying heads.
Here's what I've found, IN GENERAL:
1) Two holes is important
2) Low exit is important
3) Grizzly head seemed to cause least reaction upon impact.
4) Double lung shot animal went less than 100 yards and usually less then 75.
5) 3 blade heads produced the most blood, no contest.
6) I don't think I could calculate a difference between length of travel between 2 blade heads and 3 blade heads.
7) If there's a high entrance, but no exit, 3 blade caused more blood to follow.
8) Three blade and two blade would stop on off shoulder knuckle/brisket bone and I don't think I could say one had an advantage over the other--both had only one hole in the deer.
9) I can always shave hair off my wrist with all my heads.
All that summarized.....I'm shooting 3 blade Kustom King Trailmakers. In the areas I hunt, I need to find the animal due to coyotes. I've learned how to sort out the trail of most deer, but on some it took good light the next morning. Now with increased yotes everywhere(and bears and wolves at Shrewhaven Lodge) I want the best trail I can get. That's a three blade head trail.